1. Field of the Invention
The present invention relates to a lighting structure of a liquid crystal panel in a gauge for a vehicle.
2. Description of the Related Art
FIG. 6 and FIG. 7 show a lighting structure of a liquid crystal panel in a gauge for a vehicle disclosed in below-described PTL 1.
The gauge 101 for a vehicle disclosed in the PTL 1 is a gauge mounted on the vehicle as a combination meter having various kinds of measuring functions such as a speed meter, a tachometer, a fuel gauge or the like. The gauge 101 for the vehicle includes, as shown in the drawings, a dial 110, a pointer member 120, a liquid crystal display panel (LCD) 130, a pointer driving part (an inner machine) 140, a plurality of pointer illuminating light sources 150 and a light source 160 for the LCD.
As shown in FIG. 7, the dial 110 has a pointer driving shaft insert hole 111 and a scale and characters 113 (see FIG. 6) corresponding to measured quantities (speed) are arranged substantially in the form of a circular arc on the pointer driving shaft insert hole 111 at a center.
The pointer driving part 140 has a pointer driving shaft 142 formed in the shape of a shaft and inserted into the pointer driving shaft insert hole 111. The pointer member 120 has a pointer main body 122 fixed to an end of the pointer driving shaft 142. Both the pointer driving shaft 142 and the pointer main body 122 are formed with a light guide material. The pointer main body 122 includes a shaft connecting part 122a (see FIG. 7) fixed to the end of the pointer driving shaft 142 and a pointer part 122b (see FIG. 6) extending in a radial direction of the dial 110 from the shaft connecting part 122a to indicate the scale. The pointer main body 122 is illuminated by illuminating lights guided to the pointer driving shaft 142.
The liquid crystal display panel 130 is arranged with a prescribed distance spaced forward from a front end of the shaft connecting part 122a so as to cover a front part of the shaft connecting part 122a. The liquid crystal display panel 130 is used for displaying other measured values than speed (vehicle information such as a travel distance).
The pointer driving part 140 is arranged in a back part of the dial 110 as shown in FIG. 7. The pointer driving part 140 rotates and drives the pointer driving shaft 142 in accordance with a measured value so that the pointer main body 122 indicates the scale corresponding to the measured value.
The plurality of pointer illuminating light sources 150 are arranged in a plurality of parts of the back part of the pointer driving shaft 142 or the dial 110. A part of the plurality of pointer illuminating light sources 150 allows the pointer driving shaft 142 to introduce the illuminating lights to illuminate the pointer main body 122. Further, a part of the plurality of pointer illuminating light sources 150 is also used as a light source for illuminating the dial 110.
As shown in FIG. 7, the light source 160 for the LCD is arranged in a position near to a back surface side of the liquid crystal display panel 130 in one end edge (a lower end edge in FIG. 7) side of the liquid crystal display panel 130 to output illuminating lights to a direction (a direction shown by an arrow mark Y1 in FIG. 7) along the back surface of the liquid crystal display panel 130.
As shown in FIG. 7, in the direction where the light source 160 for the LCD outputs the illuminating lights, a tapered plate shaped light guide member 162 is arranged which distributes the lights outputted from the light source 160 for the LCD to the back surface of the liquid crystal display panel 130.
Namely, in the gauge 101 for the vehicle disclosed in the PTL 1, according to the lighting structure which illuminates the liquid crystal display panel 130, the liquid crystal display panel 130 is irradiated with the illuminating lights outputted from the exclusively used light source 160 for the LCD by means of the light guide member 162 arranged in the back surface side of the liquid crystal display panel 130.